Hydraulic press.



T. STEVENTON. HYDRAULIC PRESS.

APPLICATION TILED OUT. 11, 1912.

1,093,084. 7 Patented Apr. 14, 1914.

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THOMAS STEVEN'ION, OF BRIDGEPORT, CONNECTICUT, ASSIGNOR TO AMERICAN GRAPI-IO-PHONE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF WEST VIRGINIA.

nYnRAnnIo PRESS.

Specification of Letters Patent.

Patented Apr. 14, 1914.

To all whom it may concern:

Be it known that I, THOMAS S'rEvEN'roN, a citizen of the United States, and a resident of Bridgeport, Fairfield county, Connecticut, have invented a new and useful Hydraulic Press, which invention is fully set forth in the following specification.

My invention relates to hydraulic presses intended primarily for pressing up disk sound-records, which latter are centrally apertured.

The object of the presentinvention is to provide a centrally-located retractile plunger for producing said central aperture.

Broadly stated, the invention consists of a two-pressure hydraulic press, comprising not only the usual press-ram, but also afloating-piston located within the press-ram and actuated by water under two different pressures, for piercing a'hole through the soundrecord or other article.

Heretofore, in manufacturing disk soundrecords, the platen of thepress ram and the head block of the press have been unbroken plane surfaces; and one of the two dies (for containing the record-matrices and the thermo-plastic stock which is to constitute the ultimate pressed sound-record) carries a centrally-located pin, in order to produce in the pressed sound-record the central aperture which the latter requires for proper centering upon the turntable of the talkingmachine, But in the operation of pressing up the thermo-plastic material, under the enormous pressure of the hydraulic press, the material of the stock is compacted so firmly against this centeringpin that, after the dies and matrices have been removed from the press, considerable efforts are required to separate them and remove the pressed soundrecord. The usual manner has been by knocking the die forcibly and repeatedly upon an anvil, so as to jar the record out of its engagement. This has always been objectionable, not only on account of the loss of time and the great muscular effort required, but also because the violent manipulations loosen the fins etc. around the edges of the pressed record, which lodge upon the face of the matrix and produce dents therein; and in subsequent pressings the stock becomes lodged in these dents, forming little lumps upon the face of the record which produce a disagreeable snappy sound when such records are played on the talking-machine.

My present invention consists of a hydraulic press equipped with a floating plunger that carries a retractile centeringpin, whereby the centering-pin is removed before the dies and their contents are taken out of the press, after which the dies and matrices can be readily separated, and the pressed record removed without the hammering and its consequent delay and injury.

Although my invention may be embodied in various forms, I shall proceed to describe one preferred embodiment thereof, in connection with the accompanying drawing, in which the single figure shown is a vertical section through the operative parts of a preferred embodiment of my improved hydraulic press.

In this drawing, 1 represents the main bed-plate of the press, from which rise four columns 2; and 3 is the cross-head carried upon said columns and constituting the stationary upper jaw of the press. The bedplate 1 is recessed to receive the press-ram 4-, which carries the platen 5 to constitute the movable lower jaw of the press. In the lower part of the bed-plate is indicated the passage-way 6 for admitting the hydraulic pressure of the water (some 2,700 pounds per square inch) to the bottom face of the press-ram 4, controlled by a three-way valve 7. The platen 5 is preferably hollow, as at 8, to admit the circulation therethrough of water, under ordinary city pressure (of, say, 40 pounds per square inch), for the purpose of cooling the platen and the dies and matrices with their thermoplastic contents. The water enters through the valve-controlled pipe 9, and escapes through valvecontrolled exit 10. The foregoing is the usual construction, and forms no part of my present invention.

According to my present invent-ion, the lower part of the press-ram 4L is chambered to receive the piston 11, which latter is properly fitted therein; from said chamber rises a central opening through the ram, to receive the plunger 12 carried by the piston 11, a suitable packing-gland being provided as indicated. In the upper end of the plunger is screwed the centering-pin 18, with a rounded tip. The parts are so proportioned that when the floating-piston 11 is at the hot tom of its stroke the nose of pin 13 lies at or below the surface of the platen 5; and the piston has sufficient travel to lift the pin 13 a. height at least equal to the thickness of the combined di-es, matrices, and contained stock, the face of the upper jaw 3 being recessed, if necessary, to receive the nose of the pin. From the cooling-chamber 8 in the platen, a passage 14 leads into the chamher in the ram, on the upper side of the pis ton.

The operation of my new press will be readily understood: The dies 15 and matrices 16 with an interposed mass 17 of thermo-plastic stock are placed on the platen, the dies being so shaped and dimensioned as to insure that the cent 'al apertures (in the dies and matrices) will register with the centering-pin 13. Thereupon, the exit 10 being open, the hydraulic pressure is admitted through the passage (3, and the first result is to lift the plunger 12 and its piston 11, thereby causing the pin 13 to pass through the registered central apertures in the dies and matrices,the pin forcing its way through the thermo-plastie stock; as soon as the piston has reached the end of its up-stroke, the continuing hydraulic pressure lifts the entire press-ram 4-, forcing the jaw 5 toward the upper jaw 3, and pressing up the sound-record between the recordmatrices, all this latter being in the usual manner. Thereafter the hydraulic pressure is cut off and the water below the press-ram escapes past the valve 7; and then the exitvalve 10 is closed, so that the pressure on the upper face of the piston 11 (being no longer opposed by the hydraulic pressure) forces the piston downward, thus withdrawing the centering-pin 13 from the dies and matrices and the contained sound-record. After the pin 13 has been thus withdrawn, and the parts have resumed the position indicated in the drawing, the dies are removed from the press and readily separated, and the pressed record is easily lifted out and then sent to the finishing-room.

I have thus described my invention with some particularity of detail, but only for the sake of clearness; since the several parts could be modified in construction and arrangement. The floating-piston with its plunger and centering-pin might be located in the stationary jaw, the parts might be inverted, and various other changes and omissions might be made, without in any sense departing from the spirit of my invention.

Having thus described my inventio-nI claim: I I In a hydraulic press comprising a chambered bed-plate and a head-piece held rigidly together, a press-ram fitted in said chamber and carrying a chambered platen at its upper end, there being a chamber in the lower part of said rain and a restricted opening leading therefrom through the top of said platen and a passage connecting the upper end of the last-named chamber with the chamber in said platen, a piston and its plunger fitted respectively in said lastnamed chamber and said opening, means for admitting hydraulic pressure to the bottom of said ram and means for admitting water under lower pressure into said platen-chamber.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

THOMAS STEVENTON. l/Vitnesses:

WV. E. LYLE, JOHN S. GRIFFITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, DQG. 

